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Harvard study reinforces link between autism and air pollution

Apart from corroborating previous scientific studies that air pollution is indeed linked to autism, it offers new insights. The new insights show that women in their third trimester might be more vulnerable if they inhale elevated levels of airborne particles emitted by power plants, fires and automobiles. These findings shed light on processes that the foetus undergoes which can lead to autism said Marc Weisskopf, senior author and associate professor of environmental and occupational epidemiology at the Harvard School of Public Health. The risk, he said, was directly proportional to the exposure rate.

He further added that the reason the foetus might be most vulnerable in the third trimester was because that was the time of neuronal growth. The third trimester is when the brain development occurs and the inhalation of smog by the mother might hamper this development.

The Harvard study was focussed on 116,000 pregnant US nurses and the tracking began in 1989. The data was collected based on where the participants lived during their pregnancies and cross-referenced with levels of air pollution for those geographical areas as recorded by the US Environmental Protection Agency.

Among the participants, the study identified 245 children who were diagnosed with autism spectrum disorder (ASD). For Carmen Sanchez, a mom whose son was diagnosed with mild autism when he was 5, only confirms her suspicions that air pollution had something to do with the diagnosis. Though her son cares about how people look at him and wants to be liked, he has trouble moving from one activity to another.

While pregnant, Sanchez lived next to a building which emitted copious amounts of soot and smoke. Her home was also near the Cross Bronx Expressway which added to the smog she was inhaling while pregnant.

Sanchez in a statement said that though she felt relief that researchers were taking the problem of autism seriously and her suspicions that the bad quality of air she breathed had something to do with the diagnosis were confirmed; she is scared nonetheless. Air pollution is a modern day problem. So how does a pregnant mother avoid such places?

Michael Rosanoff, director for public health research for the advocacy group Autism Speaks says that though the Harvard study does not raise new issue i.e. air pollution is related to autism; it does however provide the strongest evidence till date. He also says that though there is a strong link between the two, not all mothers exposed to polluted air will have autistic children. This is simply because autism is complex. There is however an underlying biology that the combination of environmental factors and autism exists which increases the risk two-fold.